1.

/**
* FWP, Ausgewählte Probleme aus dem ACM Programming Contest, WS10/11
* Problem: ##10071 ## Back to high school physics
* Link: http://uva.onlinejudge.org/index.php?option=com_onlinejudge&Itemid=8&page=show_problem&category=94&problem=1012&mosmsg=Submission+received+with+ID+8319322
*
* @author Felix Dietrich
* @version 1.0, 14.10.2010
*
* Method : Easy physics
* Status : Accepted
* Runtime: 1.232
*/

import java.util.Scanner;

public class Main
{
public static void main(String[] args)
{
Scanner sc = new Scanner(System.in);

while (sc.hasNext())
{
int v = sc.nextInt();
int t = sc.nextInt();

System.out.println(v * t * 2);
}
}
}



2.

import java.io.*;
import java.util.*;

class Main {

public static void main(String...args) throws Exception
{
BufferedReader reader = new BufferedReader(new InputStreamReader(System.in));
String input;
String s[];
long t;

while( (input = reader.readLine()) != null)
{
s = input.split(" ");
t = 2*Long.parseLong(s[0])*Long.parseLong(s[1]);
System.out.println(t);
}
}
}